CN216599116U

CN216599116U - Standby power supply circuit and electric equipment

Info

Publication number: CN216599116U
Application number: CN202123088748.6U
Authority: CN
Inventors: 熊俊玉; 张艺阳
Original assignee: Shenzhen Inovance Technology Co Ltd
Current assignee: Shenzhen Inovance Technology Co Ltd
Priority date: 2021-12-09
Filing date: 2021-12-09
Publication date: 2022-05-24
Anticipated expiration: 2031-12-09

Abstract

The utility model discloses a standby power supply circuit and electric equipment, and relates to the technical field of power electronics. The standby power supply circuit comprises a power supply end, an energy storage unit, a switch unit and an impedance unit; the power supply end is used for supplying power to the rear-stage circuit. The energy storage unit is used for storing and releasing electric charges. The switch unit, the power supply end and the energy storage unit form a discharge loop, and the switch unit is in a conducting state when the voltage of the power supply end is smaller than that of the energy storage unit. The impedance unit is connected with the switch unit in parallel, forms a charging loop with the power supply end and the energy storage unit and is used for charging the energy storage unit. The utility model reduces the voltage drop amplitude between the energy storage unit and the power supply end by utilizing the switch unit to form the discharge loop, so that the power supply end has higher voltage when the discharge starts, thereby delaying the effective discharge time and ensuring that the later stage circuit runs the established program for a longer time.

Description

Standby power supply circuit and electric equipment

Technical Field

The utility model relates to the technical field of power electronics, in particular to a standby power supply circuit and electric equipment.

Background

At present, power-down protection measures are provided for electric equipment in various fields. After the equipment loses power, some insurance measures such as data retention, information uploading and the like are carried out by utilizing the standby power supply. In order to reduce the cost, most of the standby power supplies are fast charging and discharging devices, such as various capacitor devices. However, the devices have fast discharge speed and short effective discharge time, which may cause the electric equipment not to complete the setting operation.

SUMMERY OF THE UTILITY MODEL

The utility model mainly aims to provide a standby power supply circuit and electric equipment, and aims to solve the technical problem that the effective discharge time of a standby power supply in the prior art is short.

To achieve the above object, the present invention provides a standby power supply circuit, including:

the power supply end is used for supplying power to the post-stage circuit;

an energy storage unit for storing and releasing electric charges;

the switch unit, the power supply end and the energy storage unit form a discharge loop, and the switch unit is in a conducting state when the voltage of the power supply end is smaller than that of the energy storage unit;

and the impedance unit is connected with the switch unit in parallel, forms a charging loop with the power supply end and the energy storage unit and is used for charging the energy storage unit.

Optionally, the switch unit includes:

the first communication end of the first switch tube is connected with the negative electrode of the energy storage unit, the second communication end of the first switch tube is grounded, and the positive electrode of the energy storage unit is connected with the power supply end;

and the first control circuit is connected with the control end of the first switching tube and used for controlling the first switching tube to be in a conducting state when the voltage of the power supply end is less than the voltage of the energy storage unit.

Optionally, the first switch tube is a field effect transistor, a drain of the field effect transistor is connected with a negative electrode of the energy storage unit, a source of the field effect transistor is grounded, and a gate of the field effect transistor is connected with the first control circuit.

Optionally, the first control circuit includes:

the first connecting end of the second switch tube is respectively connected with the power supply end and the grid electrode of the field effect transistor, and the second connecting end of the second switch tube is connected with the source electrode of the field effect transistor;

and the second control circuit is connected with the control end of the second switching tube and used for transmitting a control signal to the control end, the control signal is at a high level when the power supply end is connected with an external power supply, and the control signal is at a low level when the power supply end is not connected with the external power supply.

Optionally, the second switch tube is a triode, a collector of the triode is connected with the power supply end and a gate of the field effect transistor respectively, an emitter of the triode is connected with a source of the field effect transistor, and a base of the triode is connected with the second control circuit.

Optionally, the second control circuit includes:

the power supply input end is used for accessing an external power supply;

and the voltage reduction circuit is connected with the power input end and the second switching tube and used for carrying out voltage reduction treatment on an external power supply to obtain reference voltage and transmitting the reference voltage to the control end of the second switching tube.

Optionally, the voltage-reducing circuit includes: a first resistor and a second resistor;

the first end of the first resistor is connected with the power input end, the second end of the first resistor is respectively connected with the control end of the second switch tube and the first end of the second resistor, and the second end of the second resistor is grounded.

Optionally, the impedance unit comprises a thermistor, the thermistor having a positive temperature coefficient.

Optionally, the energy storage unit includes a plurality of super capacitors, and the super capacitors are connected in series.

In order to achieve the above object, the present invention further provides an electric device, which includes the above standby power supply circuit.

In the utility model, a standby power supply circuit is formed by arranging a power supply end, an energy storage unit, a switch unit and an impedance unit. The power supply end is used for supplying power to the rear-stage circuit. And the energy storage unit is used for storing and releasing electric charges. And the switching unit, the power supply end and the energy storage unit form a discharge loop, and the switching unit is in a conducting state when the voltage of the power supply end is less than that of the energy storage unit. And the impedance unit is connected with the switch unit in parallel, forms a charging loop with the power supply end and the energy storage unit and is used for charging the energy storage unit. The utility model reduces the voltage drop amplitude between the energy storage unit and the power supply end by utilizing the switch unit to form the discharge loop, so that the power supply end has higher voltage when the discharge starts, thereby delaying the effective discharge time and ensuring that the later stage circuit runs the established program for a longer time.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a block diagram of a standby power circuit according to a first embodiment of the present invention;

FIG. 2 is a block diagram of a stand-by power supply circuit according to a second embodiment of the present invention;

fig. 3 is a schematic circuit diagram of a standby power circuit according to an embodiment of the utility model.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	Power supply terminal	80	Voltage reduction circuit
20	Energy storage unit	K1～K1	First to second switching tubes
				30	Switch unit	R1～R5	First to fifth resistors
40	Impedance unit	C1～C2	First to second capacitors
				50	First control circuit	Q	Field effect transistor
60	Second control circuit	T	Triode transistor
				70	Power input terminal	RV	Thermal resistor

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should be considered to be absent and not within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a block diagram of a standby power circuit according to a first embodiment of the present invention. The utility model provides a first embodiment of a standby power supply circuit.

In the first embodiment, the standby power circuit includes a power supply terminal 10, an energy storage unit 20, a switching unit 30, and an impedance unit 40. The power supply terminal 10 is used for supplying power to a subsequent stage circuit. And an energy storage unit 20 for storing and releasing electric charges. The switching unit 30, together with the power supply terminal 10 and the energy storage unit 20, forms a discharge loop, and when the voltage of the power supply terminal 10 is less than the voltage of the energy storage unit 20, the switching unit 30 is in a conducting state. And the impedance unit 40 is connected in parallel with the switching unit 30, and forms a charging loop with the power supply terminal 10 and the energy storage unit 20 to charge the energy storage unit 20.

It should be noted that the standby power circuit can be disposed in various electric devices, such as an industrial personal computer, an intelligent electrical appliance, and the like. When the electric equipment is powered on, the power supply terminal 10 can access an external power supply, which can be mains power or a power supply provided by a power conversion device. When the power consumption device is powered down, the power supply terminal 10 loses the supply of the external power. The later stage circuit may be a core circuit of the electric device, which may include an actuator driving circuit or a core control circuit of the electric device, and the like.

In a specific implementation, the energy storage unit 20 may be formed by a capacitor. For example, the energy storage unit 20 may be formed by connecting a plurality of super capacitors in series. When the power supply terminal 10 is connected to an external power supply, the energy storage unit 20 is charged by the external power supply incoming line. When the energy storage unit 20 is charged, a charging current flows through the power supply terminal 10, the energy storage unit 20 and the impedance unit 40. The charging voltage is equal to the external power source, and the magnitude of the charging current is related to the resistance value of the impedance unit 40. In addition, to ensure normal charging, the switching unit 30 is in an off state when the energy storage unit 20 is charged (i.e. the voltage of the power supply terminal 10 is greater than the voltage of the energy storage unit 20).

It should be noted that the charging process of the energy storage unit 20 usually occurs when the electric device is in the on state. And after the electric equipment is connected with an external power supply, the rear-stage circuit starts. At this time, the charging current of the energy storage unit 20 cannot be too large, otherwise, slow power-on of the electric device may be caused. As can be seen from the foregoing, the magnitude of the charging current is related to the resistance value of the impedance unit 40, so that the resistance value of the impedance unit 40 can be set as small as possible. In a specific implementation, the resistance unit 40 may be composed of a thermistor having a positive temperature coefficient, and the resistance value is higher as the characteristic temperature is higher. When the energy storage unit 20 starts to charge, the instantaneous current is large, the thermistor heats, the internal resistance increases, the charging current decreases accordingly, the heating decreases, the internal resistance decreases, the charging current increases, and finally a dynamic balance is achieved. Therefore, by selecting a thermistor with appropriate parameters, the charging time of the energy storage unit 20 can be greatly reduced. Secondly, the thermistor package is smaller than a common resistor, so that the area of a Printed Circuit Board (PCB) can be reduced, and the product cost is reduced.

It can be understood that, since the power supply terminal 10, the energy storage unit 20 and the impedance unit 40 form a path, when there is no switch for control, if the energy storage unit 20 is completely charged, the power supply terminal 10 loses the external power supply, or when the voltage of the external power supply suddenly decreases, since the voltage of the power supply terminal 10 is less than the voltage of the energy storage unit 20, the energy storage unit 20 will discharge to the power supply terminal 10 through the impedance unit 40. At this time, the subsequent stage circuit can still operate for a period of time.

The time during which the subsequent circuit can normally operate during the discharging process of the energy storage unit 20 may be referred to as an effective discharge time. Assuming that the power supply terminal 10 completely loses the external power supply, the initial voltage of the energy storage unit 20 is V, and the lowest operating voltage of the subsequent circuit is V1, the effective discharge time corresponds to the decay time corresponding to the voltage of V-V2-V1. Where V2 is the voltage of the impedance unit 40. Since the voltage decay rate is constant, the length of the decay time is related to the initial voltage of the power supply terminal 10 at the start of discharge. In the above case, the initial voltage V3 of the power supply terminal 10 is V-V2.

In the present embodiment, to increase the effective discharge time, the switch unit 30 is used as a loop of the discharge circuit. Since the impedance of the switching unit 30 when it is turned on is low. A large part of the discharge current flows from the switching unit 30 to the power supply terminal. At this time, the initial voltage V3 of the power supply terminal 10 becomes V-V4. Since V4 is much smaller than V2, when the switch unit 30 discharges, the initial voltage of the power supply terminal 10 is higher, i.e. the effective discharge time is longer, and the operation time of the subsequent circuit is longer.

In addition, since the impedance of the switching unit 30 is low when it is turned on, if the energy storage unit 20 is in a conductor state during charging, the charging current of the energy storage unit 20 is increased, and the subsequent circuit cannot be started up quickly. Therefore, when the energy storage unit 20 is in the charging state, the switching unit 30 is in the off state.

In the present embodiment, a standby power supply circuit is configured by providing the power supply terminal 10, the energy storage unit 20, the switching unit 30, and the impedance unit 40. The power supply terminal 10 is used for supplying power to a subsequent stage circuit. And an energy storage unit 20 for storing and releasing electric charges. The switching unit 30, together with the power supply terminal 10 and the energy storage unit 20, forms a discharge loop, and when the voltage of the power supply terminal 10 is less than the voltage of the energy storage unit 20, the switching unit 30 is in a conducting state. And the impedance unit 40 is connected in parallel with the switching unit 30, and forms a charging loop with the power supply terminal 10 and the energy storage unit 20 to charge the energy storage unit 20. In the present embodiment, the switch unit 30 is used to form a discharge loop, so that the voltage drop between the energy storage unit 20 and the power supply terminal 10 is reduced, and the power supply terminal 10 has a higher voltage when discharging starts, thereby delaying the effective discharge time and ensuring that the subsequent circuit runs the predetermined program for a longer time.

Referring to fig. 2, fig. 2 is a block diagram of a standby power circuit according to a second embodiment of the present invention. Based on the first embodiment, the present invention provides a second embodiment of the standby power supply circuit.

In the second embodiment, the switching unit 30 includes a first switching tube K1 and a first control circuit 50. The first connection end of the first switch tube K1 is connected to the negative electrode of the energy storage unit 20, the second connection end of the first switch tube K1 is grounded, and the positive electrode of the energy storage unit 20 is connected to the power supply end 10. The first control circuit 50 is connected to the control terminal of the first switch tube K1, and is configured to control the first switch tube K1 to be in an off state when the voltage at the power supply terminal 10 is greater than the voltage of the energy storage unit 20, and control the first switch tube K1 to be in an on state when the voltage at the power supply terminal 10 is less than the voltage of the energy storage unit.

In the present embodiment, a single switch tube is used to form a discharge loop with the energy storage unit 20 and the power supply terminal 10. The voltage drop of the switch tube is very constant when the switch tube is conducted, so that the initial voltage of the power supply end 10 during discharging is improved, and the effective discharging time is prolonged. Of course, the first switch tube K1 may also be disposed between the energy storage unit 20 and the power supply terminal 10, and the negative electrode of the energy storage unit 20 is grounded.

Meanwhile, referring to fig. 3, fig. 3 is a schematic circuit diagram of an embodiment of the standby power circuit of the present invention. In a specific implementation, the first switch tube K1 is a field effect transistor Q, a drain of the field effect transistor Q is connected to a negative electrode of the energy storage unit 20, a source of the field effect transistor Q is grounded, and a gate of the field effect transistor Q is connected to the first control circuit 50.

It will be appreciated that the field effect transistor Q has a lower turn-on voltage than transistors and diodes, which can be on the order of mV. Therefore, the field effect transistor Q, the energy storage unit 20 and the power supply terminal 10 form a discharge loop, so that the power supply terminal 10 has a higher initial voltage when discharging.

The first control circuit 50 may control the first switch tube K1 by outputting a high-low level. The corresponding relationship between the high and low levels and the state of the first switch tube K1 can be set according to the requirement, for example, when the first control circuit 50 outputs the high level to the first switch tube K1, the first switch tube K1 is in the conducting state, or when the first control circuit 50 outputs the low level to the first switch tube K1, the first switch tube K1 is in the conducting state. Taking the field effect transistor Q in fig. 3 as an example, the gate of the field effect transistor Q is in a conducting state when receiving a high level.

In a specific implementation, the first control circuit 50 may include a second switching tube K2 and a second control circuit 60. A first connection terminal of the second switch tube K2 is connected to the power supply terminal 10 and the gate of the field effect transistor Q, respectively, and a second connection terminal of the second switch tube K2 is connected to the source of the field effect transistor Q. And the second control circuit 60 is connected to the control terminal of the second switching tube K2, and is configured to transmit a control signal to the control terminal, where the control signal is at a high level when the power supply terminal 10 is connected to an external power supply, and the control signal is at a low level when the power supply terminal 10 is not connected to the external power supply.

In this embodiment, the second switching tube K2 is connected between the gate and the source of the field effect transistor Q. When the second switch transistor K2 is in the on state, the gate and source voltages of the field effect transistor Q are the same, and the field effect transistor Q is in the off state. Meanwhile, in order to enable charging and discharging control to be more accurate, the state of the field effect transistor Q can be synchronized with the power supply condition of an external power supply. That is, the electric equipment is connected with an external power supply, the field effect transistor Q is in an off state, the second switch tube K2 is in an on state, when the electric equipment loses the external power supply connection, the field effect transistor Q is in the on state, and the second switch tube K2 is in the off state.

In a specific implementation, the second switch tube K2 may be a transistor T, a collector of the transistor T is connected to the power supply terminal 10 and a gate of the field effect transistor Q, an emitter of the transistor T is connected to a source of the field effect transistor Q, and a base of the transistor T is connected to the second control circuit 60.

It will be appreciated that when the control signal is high, the transistor T is on and the field effect transistor Q is off. When the control signal is at a low level, the triode T is turned off, the gate of the field effect transistor Q is introduced into the voltage of the power supply terminal 10 through the third resistor, and the field effect transistor Q is in a conducting state because the voltage of the power supply terminal 10 is the voltage of the energy storage unit 20 at this time.

In a specific implementation, the second control circuit 60 may include a power input 70 for accessing an external power source. And the voltage reduction circuit 80 is connected with the power input end 70 and the second switch tube K2, and is used for performing voltage reduction processing on an external power supply, obtaining a reference voltage, and transmitting the reference voltage to the control end of the second switch tube K2.

In the present embodiment, the external power supply is directly applied to the control terminal of the second switching tube K2 as an input signal. Meanwhile, in order to prevent the external power supply from being excessively high in voltage, the external power supply is converted by the voltage-reducing circuit 80. When the electric equipment is connected with an external power supply, the control end of the second switch tube K2 is at a high level, the second switch tube K2 is in a conducting state, and otherwise, the second switch tube K2 is in a disconnecting state.

In particular implementations, the voltage dropping circuit 80 may include a first resistor R1 and a second resistor R2. A first end of the first resistor R1 is connected to the power input terminal 70, a second end of the first resistor R1 is connected to the control terminal of the second switch tube K2 and the first end of the second resistor R2, and a second end of the second resistor R2 is grounded.

It can be understood that the first resistor R1 and the second resistor R2 form a voltage dividing circuit, and a slightly lower voltage is obtained by dividing the voltage of the external power source and is transmitted to the control terminal of the second switch tube K2.

In this embodiment, the energy storage unit 20 may include two first capacitors C1 and a second capacitor C2 connected in series, and each of the first capacitor C1 and the second capacitor C2 is a super capacitor. The first capacitor C1 and the second capacitor C2 are further connected in parallel with a fourth resistor R4 and a fifth resistor R5, respectively. One end of the second capacitor C2 is also connected with a thermistor RV, and one end of the thermistor RV is grounded.

When the electric equipment is in a power-on state, and the power supply terminal 10 is connected with an external power supply, the field effect transistor Q is in a disconnected state, and the power supply terminal 10 charges the first capacitor C1 and the second capacitor C2 through the thermistor RV. When the electric equipment is in a power-down state, the power supply terminal 10 loses the external power supply, the field effect transistor Q is in a conducting state, and the first capacitor C1 and the second capacitor C2 discharge to the power supply terminal 10 through the field effect transistor Q.

In the present embodiment, the switching unit 30 includes a first switching tube K1 and a first control circuit 50. The first connection end of the first switch tube K1 is connected to the negative electrode of the energy storage unit 20, the second connection end of the first switch tube K1 is grounded, and the positive electrode of the energy storage unit 20 is connected to the power supply end 10. The first control circuit 50 is connected to the control terminal of the first switch tube K1, and is configured to control the first switch tube K1 to be in an off state when the voltage at the power supply terminal 10 is greater than the voltage of the energy storage unit 20, and control the first switch tube K1 to be in an on state when the voltage at the power supply terminal 10 is less than the voltage of the energy storage unit. The discharge loop is formed with the energy storage unit 20 and the power supply terminal 10 by using a single switching tube. The voltage drop of the switch tube is very constant when the switch tube is conducted, so that the initial voltage of the power supply end 10 during discharging is improved, and the effective discharging time is prolonged.

In order to achieve the above object, the present invention further provides an electric device, which includes the above standby power supply circuit. The specific structure of the standby power supply circuit refers to the above embodiments, and since the electric device can adopt the technical solutions of all the above embodiments, the electric device at least has the beneficial effects brought by the technical solutions of the above embodiments, and details are not repeated herein.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A backup power supply circuit, characterized in that the backup power supply circuit comprises:

the power supply end is used for supplying power to the post-stage circuit;

an energy storage unit for storing and releasing electric charges;

the switch unit, the said power supply end and the said energy storage unit form the discharge circuit, the said switch unit is in the conducting state when the voltage of the said power supply end is smaller than the voltage of the said energy storage unit;

2. The backup power supply circuit according to claim 1, wherein the switching unit includes:

a first connection end of the first switch tube is connected with the negative electrode of the energy storage unit, a second connection end of the first switch tube is grounded, and the positive electrode of the energy storage unit is connected with the power supply end;

3. The backup power supply circuit according to claim 2, wherein the first switching transistor is a field effect transistor, a drain of the field effect transistor is connected to a negative electrode of the energy storage unit, a source of the field effect transistor is grounded, and a gate of the field effect transistor is connected to the first control circuit.

4. The backup power supply circuit of claim 3, wherein the first control circuit comprises:

a first connection end of the second switch tube is respectively connected with the power supply end and the grid electrode of the field effect transistor, and a second connection end of the second switch tube is connected with the source electrode of the field effect transistor;

5. The backup power supply circuit according to claim 4, wherein said second switching transistor is a transistor, a collector of said transistor is connected to said power supply terminal and a gate of said field effect transistor, respectively, an emitter of said transistor is connected to a source of said field effect transistor, and a base of said transistor is connected to said second control circuit.

6. The backup power supply circuit of claim 4, wherein the second control circuit comprises:

the power supply input end is used for accessing the external power supply;

and the voltage reduction circuit is connected with the power input end and the second switch tube and used for carrying out voltage reduction treatment on the external power supply to obtain reference voltage and transmitting the reference voltage to the control end of the second switch tube.

7. The backup power supply circuit of claim 6, wherein the voltage-reduction circuit comprises: a first resistor and a second resistor;

8. The backup power circuit of any of claims 1-7, wherein said impedance unit comprises a thermistor, said thermistor having a positive temperature coefficient.

9. The backup power circuit according to any of claims 1-7, wherein said energy storage unit comprises a plurality of super capacitors, each super capacitor being connected in series with each other.

10. An electrical consumer, characterized in that the electrical consumer comprises a backup power supply circuit according to any one of claims 1-9.